COMPARISON OF LIGHT, REGULAR AND HEAVY SERIES HELICAL SPRING LOCK WASHER*
Earnest Machine Products line of “Light Series” Helical Spring Lock Washers are manufactured to the same material and hardness requirements of “Regular” and “Heavy” series lock washers per ANSI/ASME B18.21.1 (Hardness Rc 38/46). Light Series are designed to handle the loads developed by SAE Grade 2 and 5 Cap Screw assemblies as well as ASTM A307, A325, A449 and A354 BC assemblies.
The smaller outside diameter reduces the clearance that is needed for the regular series lock washers. The lower profile also reduces the clearance needed of the head of the assembly.
“Regular” and "Heavy" Series Lock Washers are recommended for use in assemblies of strengths up to Grade 8, A490 and A354 BD. The “Heavy Series” Lock Washers are designed to increase the length of the assembly of the fastener and provide increased spring rate in the joint. The added thickness also helps to resist opening up when the higher torques needed to preload high strength and structural fasteners are used.
* Thickness = (t0 + tI)/2
Nom.
Size |
Light Series |
Regular
(Medium) Series |
Heavy Series |
| ID |
OD |
Thickness* |
W |
ID |
OD |
Thickness* |
W |
ID |
OD |
Thickness* |
W |
| Min |
Max |
Min |
Nom |
Min |
Max |
Min |
Nom |
Min |
Max |
Min |
Nom |
| 1 5/8 |
1.633 |
2.487 |
.344 |
.391 |
1.633 |
2.553 |
.389 |
.424 |
1.633 |
2.694 |
.458 |
.491 |
| 1 3/4 |
1.758 |
2.613 |
.344 |
.391 |
1.758 |
2.679 |
.389 |
.424 |
1.758 |
2.820 |
.458 |
.491 |
| 2 |
2.008 |
2.840 |
.384 |
.393 |
2.008 |
2.936 |
.422 |
.427 |
2.008 |
3.144 |
.496 |
.526 |
| 2 1/4 |
2.262 |
3.195 |
.422 |
.427 |
2.262 |
3.221 |
.440 |
.442 |
2.262 |
3.398 |
.496 |
.526 |
| 2 1/2 |
2.512 |
3.145 |
.422 |
.427 |
2.512 |
3.471 |
.440 |
.442 |
2.512 |
3.648 |
.496 |
.526 |
| 2 3/4 |
2.762 |
3.758 |
.458 |
.458 |
2.762 |
3.824 |
.458 |
.491 |
2.762 |
3.910 |
.526 |
.532 |
| 3 |
3.012 |
4.008 |
.458 |
.458 |
3.012 |
4.074 |
.458 |
.491 |
3.012 |
4.160 |
.526 |
.532 |